The present invention provides a valve bushing cleaning device and a method for cleaning a valve bushing to remove solid particles from apertures in the valve bushing wall while the bushing is situated in a valve bore of a valve body, the valve body having fluid passages therein which communicate with the valve bore.
The valve bushing cleaning device is usable to clean the valve bushings that are contained in a valve body of various braking devices, such as the fluid pressure braking devices used in vehicles, such as trucks, and in railway vehicles. A primary use, however, is in the cleaning of valve bushings of a railway vehicle fluid pressure braking device, whether for new valve bushings in the assembly of original equipment or for rebuilt or serviced valve bushings in existing equipment.
In a fluid pressure brake apparatus for railway vehicles, such as brake controls for an electric or diesel-electric locomotives when used in freight service, passenger service or as switchers and controlling brakes on a multiple unit, such as subway cars, the apparatus contains valve bores that communicate with passages in a valve body, with valve bushings having apertures through the wall thereof, selectively charging fluid, such as air, to various passages to effect operation of brake components. Such a fluid pressure brake apparatus is described, for example, in U.S. Pat. No. 2,958,561, issued Nov. 1, 1960 to Harry C. May and in U.S. Pat. No. 3,504,950, issued Apr. 7, 1970 to Glenn T. McClure, both of which were assigned to the assignee of the present invention, and the contents of both said patents are incorporated by reference herein. The brake apparatus described in these two patents has been designated in the industry as the 26 Brake Valve and has been in use for a period of time. This air brake device is tested for discharge at regular intervals without removing the brake valve from a locomotive.
At periodic intervals, namely within any twenty-four month period of operation, the brake valve is removed from the equipment and is completely dismantled, with the various parts of the brake valve cleaned, inspected, lubricated, reassembled and tested. New rubber parts, such as O-ring seals and other new parts, as specified in maintenance specifications are inserted at this time.
It has been found, during periodic maintenance intervals, that bushings used in the brake valve, which have passageways through the wall of the bushing, can collect minute particles of rubber components, which may have worn or deteriorated to an extent from O-ring seals, and also minute rust or scale particles that result from condensation or other oxidation in the brake valve device. Such minute solid particles which have usually collected in the interior chamber of a valve bushing, or in the valve chamber can find their way into the passageways through the wall of the valve bushing and cause plugging of such passageways. The cleaning of the valve bushings and valve chambers is generally carried out by soaking the valve device in a solvent, such as mineral spirits, and then forcing air through passages in the valve body to dislodge minute particles. This procedure, however, poses a problem in that minute particles can become entrapped in passageways in the wall of the valve bushing which requires that the bushing be removed from the valve chamber, cleaned separately and then returned to the valve chamber, which results in added expense in time and labor involved.
It is an object of the present invention to provide a valve bushing cleaning device that can be used to clean a valve bushing that is positioned in a valve bore of a valve body.
It is another object of the present invention to provide a method for cleaning a valve bushing that is positioned in a valve bore of a valve body.